This invention relates to chemical injection means for fire fighting and more particularly to an automatic electrically controlled system for providing a desired ratio of chemicals to total flow.
Foam or other type chemicals are frequently added to the water used in fighting fires. A desired ratio of chemcials to total flow is desirable but this is difficult to achieve and maintain since the total flow is liable to change quite often, for instance, due to change in the supply pressure or due to the adding or subtracting of hoses from the water supply.
Conventional chemical injection apparatus generally uses manually operated mechanical mixing apparatus.